Stihl FS 361 C-M Owner's Instruction Manual page 14

English
Fuel Spraying or "Geysering"
WARNING
￭ Removing the cap on a pressurized fuel tank can result in
gasoline, vapors and fumes being forcefully sprayed out
from the fuel tank in all directions. The escaping gasoline,
vapors or fumes can cause serious personal injury,
including fire and burn injury, or property damage.
￭ Sometimes also referred to as "fuel geysering," fuel
spraying is an expulsion of fuel, vapors and fumes which
can occur in hot conditions, or when the engine is hot, and
the tank is opened without allowing the trimmer /
brushcutter to cool adequately. It is more likely to occur
when the fuel tank is half full or more.
￭ Pressure is caused by fuel and heat and can occur even if
the engine has not been running. When gasoline in the
fuel tank is heated (by ambient temperatures, heat from
the engine, or other sources), vapor pressure will increase
inside the fuel tank.
￭ Some blends of gasoline, particularly winter blends, may
cause tanks to pressurize more quickly or create greater
pressure. At higher altitudes, fuel tank pressurization is
more likely.
How to Avoid Fuel Spraying
WARNING
￭ Removing the fuel cap on a pressurized tank can result in
gasoline, vapors and fumes being forcefully sprayed out
from the fuel tank in all directions. To reduce the risk of
burns, serious injuries or property damage from fuel
spraying:
– Follow the fueling instructions in this chapter.
– Always assume your fuel tank is pressurized.
– Allow the trimmer / brushcutter to cool before
removing the fuel cap.
– If you need to refuel before completing a job, turn off
the machine and allow the engine to cool before
removing the fuel cap. In hot environments, cooling
will take longer. The engine is air cooled. When it is
12
5 IMPORTANT SAFETY INSTRUCTIONS
shut off, cooling air is no longer drawn across the
cylinder and the engine temperature will rise for
several minutes before starting to cool.
￭ After the trimmer / brushcutter has cooled appropriately,
follow the safety instructions in this chapter for removing
the cap.
– Never remove the cap by turning it directly to the
open position.
– First check for residual pressure by slowly turning
the cap approximately 1/2 turn counter-clockwise.
– The cap should be held in place by the threads while
allowing residual vapor/pressure to be relieved.
– Once any residual pressure has been relieved, turn
the cap until it can be removed from the tank
opening.
– Use only good quality fuel that is appropriate for the
season (summer v. winter blends). Some blends of
gasoline, particularly winter blends, are more volatile
and can contribute to fuel spraying.
Removing the Threaded Fuel Filler Cap
WARNING
￭
0458-838-8601-A